On 05/21/2018 05:54 AM, Alexey Dokuchaev wrote:
Hi,
I'm seeing somewhat confusing results here with 9.6.8, and cannot find
the answer in the docs or google.
I'm returning JSON array (or any array, it does not make a difference)
from my plpgsql function like this:
OUT retcode int,
OUT result json)
. . .
result := json_agg(_) FROM (
SELECT foo, bar, baz ...
FROM t1, t2, t3 WHERE ...) AS _; -- this works fine
GET DIAGNOSTICS retcode = ROW_COUNT; -- always returns 1
I'd expected `retcode' to contain the number of SELECT'ed rows, but it
is something else (always 1). Apparently, aggregation functions like
json_agg()/array_agg() mangle the ROW_COUNT from the inner SELECT (the
one I'm interested in).
Is this expected and correct behavior? Is it possible to obtain the
first ROW_COUNT (after SELECT) without performing it twice? Thanks,
Off the top of my head:
SELECT count(*) as ct, foo, bar, baz ...
retcode = result ->'ct'
./danfe
--
Adrian Klaver
adrian.klaver@xxxxxxxxxxx
